The invention discloses a computer system having voice-control function. The computer system includes a voice-recognition module, a shared memory, a microcontroller, a power-management module and a central processing unit. The voice-recognition module receives an external voice signal via a microphone and determines whether the external voice signal corresponds to an operation instruction. The shared memory is used for storing shared state information. The microcontroller is used for setting the shared state information according to the operation instruction when the external voice signal corresponds to the operation instruction. The power-management module generates a power-management signal according to the shared state information in the shared memory. When the power-management module transmits the power-management signal, the central processing unit executes a processing operation corresponding to the operation instruction according to the shared state information in the shared memory.